1. Field of the Invention
This invention relates to a method of processing heavy hydrocarbon oils, such as crude oil, crude oil residue, shale oil, tar sand bitumen, liquid conversion products obtained by the hydrogenation, gasification and degasification of coal, which oils may contain asphaltenes, heavy metals and/or other catalyst poisons, such as arsenic, antimony, selenium and the like, to produce fractions which boil below the feedstock and are subsequently processed to fuels and/or petrochemical products, such as olefins, aromatic compounds, etc.
2. Discussion of Prior Art
The known methods of processing heavy hydrocarbon oils which have very high contents of high-boiling components or asphaltenes, heavy metals and/or elements of the arsenic group are not satisfactory and not sufficiently flexible regarding the yield-distribution and the removal of metals.
It has been proposed to process such feedstocks by an expensive catalytic hydrogenation in the liquid phase and/or by de-asphaltization whereby asphaltenes are converted, catalyst poisons are removed and products are obtained which can be processed further by known methods.
These proposals have the disadvantage that the catalytic hydrogenation in the liquid phase involves the need for regenerating the catalyst and that this can be accomplished only with great difficulty if the feedstock has extremely high contents of asphaltenes, metals and trace elements. The use of one-way-catalysts necessarily involves besides the loss of the catalyst hydrocarbon oil losses since the latter must be recovered from the waste sludge formed by the hydrogenation in the liquid phase. Additionally, the activity of the one-way catalysts in question is often insufficient so that the performance of the process is adversely affected.
It is also known to de-asphaltize the heavy hydrocarbon oil for a recovery of hydrocarbon oils which are substantially free from asphaltenes and can be processed further. These processes involve the disadvantage that the yields are substantially restricted and an excessively large asphalt fraction is formed, which offers only a few possibilities for further processing. These proposals do not ensure the required removal of metals and trace elements if the feedstocks have very high contents of asphaltenes, metal and/or other trace elements which constitute catalyst poisons (Offenlegungsschrift Nos. 2,504,487; 2,508,488; 2,644,721 and 2,726,490).
It is an object of the invention to avoid these disadvantages of the prior art and to provide a process which can be carried out in a simple manner and with which the quality requirements set forth can be met with a high yield.